Each day thousands of Americans are victims of cardiac emergencies. Cardiac emergencies typically strike without warning, oftentimes striking people with no history of heart disease. The most common cardiac emergency is sudden cardiac arrest (“SCA”). It is estimated more than 1000 people per day are victims of SCA in the United States alone.
SCA occurs when the heart stops pumping blood. Usually SCA is due to abnormal electrical activity in the heart, resulting in an abnormal rhythm (arrhythmia). One such abnormal rhythm, ventricular fibrillation (VF), is caused by abnormal and very fast electrical activity in the heart. During VF the heart cannot pump blood effectively. Because blood may no longer be pumping effectively during VF, the chances of surviving decreases with time after the onset of the emergency. Brain damage can occur after the brain is deprived of oxygen for four to six minutes.
Applying an electric shock to the patient's heart through the use of a defibrillator treats VF. The shock clears the heart of the abnormal electrical activity (in a process called “defibrillation”) by depolarizing a critical mass of myocardial cells to allow spontaneous organized myocardial depolarization to resume.
Cardiac arrest is a life-threatening medical condition that may be treated with external defibrillation. External defibrillation includes applying electrodes to the patient's chest and delivering an electric shock to the patient to depolarize the patient's heart and restore normal sinus rhythm. The chance a patient's heart can be successfully defibrillated increases significantly if a defibrillation pulse is applied quickly.
In a scenario where a paramedic is responding to an emergency call with a non-specific patient condition, for example, there has been a car accident. The paramedic will typically carry his or her own defibrillator/monitor, a gurney, and drug box, and other supplies considered essential. If, perhaps, the car has driven off an embankment, the paramedic will have a long distance to run with all this equipment. This slows the response time to a call where someone may be bleeding to death. Smaller lighter equipment is always demanded by paramedics to save them time and effort, and allow them to get to the scene earlier. For just this reason, some paramedics will opt to carry only an AED (Automatic External Defibrillator) to the scene, and move the patient into the ambulance as quickly as possible, where other, more advanced monitoring equipment is available. In some countries, this approach has been incorporated into standard operating protocols, where the ambulance carries both ALS (advanced life support) equipment (which typically would include a multi-parameter monitor and defibrillator) and an AED. This approach, while effectively giving the user the choice of equipment to carry, forces the paramedic to learn two different defibrillators. The approach also forces the paramedics to possibly transfer the patient from one machine to the other once in the ambulance. It also adds costs to the ambulance service and potentially causes lost data between the two defibrillators for critical minutes, which may negatively impact the ability of EP Lab (Electro-Physiology Lab) doctors to determine the original cardiac condition.
Previous attempts to address the issue of product weight have done so by creating a manual defibrillator that separates from a patient monitor, or an AED, which separates from a single-channel patient monitor, or a manual defibrillator/pacemaker that separates from a 12-lead ECG monitor. These products suffer from limitations by the present standards, such as: limited capture of patient data, limited ability to monitor all necessary patient vital signs, and possible unreliability due to the nature of the electrical contacts between the two devices (e.g., dirt, mud, and damage to the case which could affect alignment of electrical contacts, thus preventing full functionality of the devices when mated).
Another problem arises when hospital personnel want to charge the batteries of the defibrillator/monitor, but don't want to have to place the unit in a docking station in order to charge the batteries. There also arises the issue of patient confidentiality, such as recently raised by the Federal HIPAA (Health Insurance Portability and Accountability Act) regulations, when identical looking patient monitors are accidentally swapped by users.